AirComm Corporation Airbus AS350 Air Conditioner Instructions for Continued Airworthiness User Manual

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 23 
 
Figure 4-15 – Plumbing Installation, Side Mount Condenser 
(Aft Cabin Bulkhead – View Looking Forward) 
* 
ES26194
-24 
Bypass Valve
 
*For systems supplied after March 2014 the Tee fitting shown is replaced by
 
ES40634
-7 Tee fitting and ES49035
-1 pressure relief valve
  
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 24 
 
Figure 4-16 – Air Conditioning System Plumbing – Side Mounted Condenser  
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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Figure 4-17 – Plumbing Installation, Tail Boom Condenser 
 
 
 
 
Figure 4-18 – Drier Bottle Installation, Tail Boom Condenser 
 
Looking forward at cabin aft bulkhead 
AS350-5004-T22 #8 TUBE ASSY 
AS350-5004-T23 #6 TUBE ASSY 
AS350-5004-T20 #8 TUBE ASSY 
AS350-5004-T21 #8 TUBE ASSY 
A119-5020-3 TEE FITTING 
ES26194-24 BYPASS VALVE 
AS350-5004-T7 #8 TUBE ASSY FROM COMPRESSOR 
Looking up below right 
side equipment bay 
S-6901EC-1 HEADER S-5013EC-1 Y FITTING W/ ES49035-1 PRESSURE RELIEF VALVE 
ES43042-1 DRIER BOTTLE 
From condenser 
To condenser 
From FWD evap 
To FWD evap  
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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Figure 4-19 - Air Conditioning System Plumbing –Tail Boom Condenser 
  
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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Figure 4-20 – A/C Relay Panel Location 
(RH Baggage Compartment Forward Bulkhead – View Looking Fwd) 
 
  
AS350-8420—1 / -2 
A/C Relay Panel  
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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CHAPTER 5 
PLACARDS AND MARKINGS 
1. Placard and Marking Information 
 
 
Charging Instructions Placard 
(Transmission Deck Adjacent to Aft Evaporator) 
 
NOTE 
Newer placards do not include the “BOULDER, 
COLORADO” and may include the use of Ultra PAG oil. 
 
 
 
 
Belt Alignment Caution Placard 
(Transmission Deck Adjacent to Compressor) 
 
2.4 1.1  
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
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Rear Baggage Compartment Placard (Located inside of the aft cargo door.) 
If equipped with the tail boom mounted condenser assembly 
 
 
 
 
 
Storage Bin Placard (Located inside right side of storage bin.) 
If equipped with the tail boom mounted condenser assembly and the optional storage bin 
located below the condenser 
   
						

							AIR CONDITIONER SERVICE MANUAL AS350-200M-1 
Revision 6 Page 30 
 
 
CHAPTER 6 
SERVICING 
1. Safety Precautions 
 
CAUTION 
Refrigeration servicing should be performed by qualified personnel only. 
 
The  refrigerant  used  in  the  air  conditioning  system  is  the  environmentally  safe  HFC 
R134a.  This refrigerant  is  non-explosive,  non-flammable,  and  non-corrosive,  has 
practically  no  odor,  and  is  heavier  than  air.  Although  R134a  is  classified  as  a  safe 
refrigerant,  certain  precautions  must  be  observed  to  protect  the  parts  involved  and  the 
person working on the system. 
 
Liquid  R134a  at  normal  atmospheric  pressure  and  temperature  evaporates  quickly and 
tends  to  freeze  anything  that  it  contacts.  Care  must  be  taken  to  prevent  any  refrigerant 
from coming into contact with the skin and the eyes. 
 
WARNING 
Always wear  safety  goggles  when  servicing  any  part  of  the  refrigerant 
system.  Should  any  liquid  refrigerant  contact  the  skin  or  eyes,  seek 
medical attention immediately even if the irritation ceases. 
 
WARNING 
Never  weld,  use  a  flame-type  leak  detector,  blow  torch,  solder,  steam 
clean, bake on aircraft finish, or use excess amounts of heat on, or in the 
immediate area of refrigerant supply tank. 
 
2. Servicing Information 
 
A list of suggested servicing equipment is provided later in this chapter. 
 
Servicing Procedure 
 
A. Connect  the  service  manifold  and  vacuum  pump  to  the  service  ports  located  in the 
forward transmission area adjacent to the aft evaporator. 
 
B. Turn  on  the  vacuum  pump  and  open  both  valves  to  evacuate  the  system.  When  the 
pressure  drops  to  29.40  InHg  (1.9 KgCm)  moisture  vaporizes  and  is  drawn  out  of  the 
system  by  the  vacuum  pump.  Complete  removal  of  moisture  is  important  to  prevent 
blockage of the expansion valves with ice. Leak check the system as described later in 
this chapter. 
 
NOTE 
Due  to  the  drop  in  atmospheric  pressure  with  an  increase  in  altitude,  the 
normal  vacuum  reading  will  drop  approximately  1”  InHg  (1  KgCm)  for 
each 1000 ft. (304.8 m) of altitude. 
  
						

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C. After the system has been evacuated, turn off both manifold valves and turn the vacuum 
pump off. Allow a minimum of one hour to check for vacuum leaks (if the system will not 
hold a vacuum, the system has a fitting leak). It may be necessary to charge the system 
with one or two lbs. (.45 to .86 Kg.) of refrigerant and conduct a leak check survey using 
an electronic leak detector. 
 
CAUTION 
It  is  mandatory  that  the  system  be  leak  free  to  insure  trouble  free 
operation. Continuous operation of the system with insufficient charge will 
result in reduced compressor life. 
 
D. After  the  system  is  proven  to  be  leak free,  the  system  should  be  evacuated  for  a 
minimum of 1/2 hour before being charged with HFC R134a. 
 
E. Charging  the  system  with 2.4 lbs.  (1.1 Kg.) of R134a  refrigerant  is  the  most  accurate 
method  of  charging.  This  should  be  accomplished  using  the  suggested servicing 
equipment called out in this chapter. 
 
F. If  a  charging  station  is  unavailable,  the  following  procedure  should  be  followed.  Add  an 
initial  refrigerant  charge  of  2.0  lbs.  (0.9  Kg.)  then  continue  to  add  refrigerant  until  the 
evaporator  outlet  air  temperature  and  system  suction  pressures  reach  a  minimum. 
When  adding  the  refrigerant  after  the  initial  charge,  it  should  be  done  in  increments  of 
0.2  lbs.  (.09  Kg.)  and  two  minutes  allowed  to  elapse  before  adding  each additional  0.2 
lbs.  (.09  Kg.)  refrigerant charge.  The  optimum  charge  occurs  when  evaporator  outlet 
temperatures  are  at  their  lowest.  Any  additional  refrigerant  will  cause  the  outlet  air 
temperature to increase and system performance to be degraded. 
 
WARNING 
If  the  system  is  to  be  charged  by operating  the  compressor,  it  must  be 
charged  through  the  Lo  (Blue  fitting)  pressure  (suction)  port  only. Do  not 
open  the  Hi  (Red  fitting)  pressure  (discharge)  valve  while  the  system  is 
operating. 
 
G. Test-run the system after charging, to confirm the system is working properly. 
 
CAUTION 
When  reclaiming  refrigerant be  sure  to  note  any  oil that  is  removed  from 
the system and replace the lost oil before or during re-servicing. Reduced 
compressor life will result if the total system oil charge is not maintained. 
 
SYSTEM REFRIGERANT & OIL CHARGE 
System Description Refrigerant Charge Oil Charge 
EC130 Air Conditioner system 2.4 lbs. 1.1 kg. 8.0 fl oz. 238 ml. 
 
   
						

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3. Lubrication Information 
 
The total system oil charge is 8.0 fl oz. (238 ml.) of Double End Capped Polyalkylene Glycol 
(DEC PAG). The oil is initially contained within the compressor as shipped from the factory 
so no additional oil is required when installing a new system.  
 
If oil is spilled during installation / maintenance, or is lost due to a leak in the system, it is 
necessary to approximate the amount of lost oil and add this amount to the system. This oil, 
if required, should be added to the compressor discharge line prior to system charging. 
 
This system may be serviced with either Polyolester (POE) or Double End Capped 
Polyalkylene Glycol (DEC PAG).  Polyalkylene Glycol is preferred due to its superior 
lubricating properties and improved compressor service life.  There are several types of  
PAG available. Only the “Double End Capped” type is permissible in Air Comm Corporation 
air conditioning systems.  Double End Capped PAG oil is available from Air Comm 
Corporation in 8 ounce bottles (P/N ES94006-13).  Mixing of POE and PAG is acceptable.  
Disregard previous statements to the contrary. They referenced PAG oil that was not 
“Double End Capped”.  Current versions of compressors are designed to be operated using 
PAG oil.  Testing by Air Comm Corporation has shown that “Double End Capped” PAG is 
compatible with POE and can therefore be mixed. “Double End Capped” is a reference to 
the chemical structure of the molecule and not to the container. 
 
(Do not use Mineral oil in this system with R134a refrigerant. Do not use any refrigerant oil 
other than Double End Capped Polyalkylene Glycol (also known as “ULTRA PAG”) or 
Polyolester (also POE)). 
 
Containers of DEC PAG or POE will absorb moisture if left open (hygroscopic). Keep 
containers tightly capped when not in use and keep all system components capped while 
servicing system. 
 
The quantity of lubrication in the system is critical. If too little lubrication is in the system the 
compressor life may be reduced. No other component in the A/C system requires 
lubrication. Too much lubricant in the system will retard heat transfer in the evaporator and 
condenser coils and reduce the cooling capacity of the system.  
 
 
NOTE 
Maintaining  the  correct  amount  of  refrigerant  and  refrigerant  oil  in  the 
system is critical for ensuring the long life of the compressor. 
 
The Service Ports for this system are located in the forward transmission deck area adjacent 
to the aft evaporator. 
 
CAUTION 
This system is serviced with either Polyester Based Refrigerant Oil (POE) or Double end 
capped Polyalkylene oil (DEC PAG, aka Ultra PAG). The use of Mineral Oil or Polyalkylene 
(PAG) in this system will cause damage to the air conditioner compressor and expansion 
valves.